There exists a growing body of evidence, both experimental and clinical, which supports the concept of intimate communication between the central nervous and immune systems to maintain homeostasis and health. Data support the fact that this interrelationship is bi-directional, such that the immune system is subject to regulation by neuroendocrine factors and vice versa. Advanced Sensor Technologies, Inc (AST) proposes to combine a number of its existing proprietary technologies to create a sensor-fitted, modular, perifusion bioreactor to perform in vitro studies to better understand and elucidate these means of cellular communication. Since AST's modular perifusion bioreactor is capable of closely mimicking in vivo conditions in vitro, the intimate communication between the nervous, endocrine, and immune systems can be elucidated. The results of this proposed research and development project will provide: (a) a commercially viable bioreactor platform that will be utilized first by the research communities (universities) followed by the development communities (drug discovery companies); (b) basic scientific insight into the axes of cellular communication. AST's sensor-fitted, modular, perifusion bioreactor is capable of monitoring the concentrations of a wide variety of biological molecules, including neurohormones such as arginine vasopressin, corticotropin releasing factor, gonadotropin releasing hormone, and beta-endorphin.